


Beyond the Stars

by ImpishTubist



Category: Sherlock (TV)
Genre: AU, Alcohol Abuse/Alcoholism, Drug Use, Implied Sexual Content, Mild Language, Violence, injuries
Language: English
Status: Completed
Published: 2012-12-13
Updated: 2012-12-13
Packaged: 2017-11-18 23:31:32
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 6
Words: 19,483
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/566507
Author URL: https://archiveofourown.org/users/ImpishTubist/pseuds/ImpishTubist
Summary: <blockquote class="userstuff">
              <p>
  <i>“You have a choice to make, Sherlock Holmes. Your friend... or your lover?”</i>
</p><p>Forty years ago, humanity left behind a dying Earth and fled to the stars. But life in space is fraught with danger, and some of it is found inside the very walls that are supposed to keep them safe.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> “Vast migrations of people--some voluntary, most not--have shaped the human condition. More of us flee from war, oppression, and famine today than at any other time in human history. As the Earth’s climate changes in the coming decades, there are likely to be far greater numbers of environmental refugees. Better places will always call to us.”
> 
> -Carl Sagan, _Pale Blue Dot_

  
Things rarely ever go just _a little bit_ wrong in space.   
  
Greg Lestrade tries very hard not to dwell on this fact, because even though he’s spent nearly his entire life in space, the idea that a thin wall is the only thing separating him from the vacuum outside still keeps him up at night.   
  
Though _thin_ is a relative term, he supposes. The outer wall of his cabin is at least two meters thick, but that’s paper-thin compared to the one hundred kilometers of atmosphere that once surrounded the long-since-abandoned Earth.   
  
He doesn’t remember much of that life, of course, having been a child when his parents fled the planet. He _does_ remember days of sunshine and weather patterns; remembers looking out of a window and seeing blue sky rather than endless night. He never gave space a second thought back then. It was always _out there_ , _elsewhere_. Not anything that could touch him, or affect his life in any way.   
  
Back on Earth, particles of dust had been harmless and gravity was a constant. Here, passing through a cloud of dust could spell disaster for them. It could tear tiny holes in their ship that might be too minute to notice at first, or too numerous to repair in time. And gravity itself is a finicky luxury. More than once, a failure in the gravity field has led to horrendous and gruesome accidents. He’s seen some of them first-hand; John Watson has had to deal with more, and Lestrade doesn’t envy him one bit.   
  
“If you don’t stop thinking right this moment,” a voice mutters from somewhere beneath a mound of blankets on his bed, tearing Lestrade from his restless thoughts, “I _will_ come over there and give the Met a brand-new case to deal with.”   
  
The mound shifts, sniffs, and adds, “And I’ll make sure they never solve it.”   
  
Lestrade, who has been sitting at his desk in order to catch up on some reading, takes off his reading glasses and rubs his face wearily. He has to be on duty in less than two hours, and he hasn’t slept in more than twenty-eight. It’s not a case that keeps him up this night; just another bout of insomnia. It is profoundly unfair, he thinks, that sleep should elude someone who wants it so badly and yet come easily to men like Sherlock Holmes, who couldn’t care less whether they slept or not.   
  
“Ship rat,” he mutters in retaliation at Sherlock’s stirring form across the room. It’s an ancient taunt that came into being more than a generation ago, when the first children born after the refugee ships took to space started to come of age. Their older schoolmates, seeking solidarity with others who remembered both earth and sky, invented the term. It has long since vanished from the playgrounds and schools; now, it only exists in the offices of the middle-aged and aging workforce. It will die out in another generation or two, when the last of the refugees passes on. In less than a century, there will be no human left alive who remembers what it was like to live on a planet.   
  
Sherlock, who has never felt the dirt between his toes nor lived without the constant threat of decompression just meters away, snorts and finally surfaces.   
  
“God, Lestrade, you _must_ be tired, if that’s the best you can come up with,” he says as he emerges from Lestrade’s bedding. He narrows his eyes in a squint at the sudden assault of light, and rakes a hand through his wild mop of hair. His eyes flick over Lestrade for a moment, and then his gaze turns accusing. “You didn’t come to bed last night.”   
  
“As though you knew the difference at the time,” Lestrade tells him with an exasperated snort. Sherlock had been fast asleep when he arrived home five hours ago and had barely even stirred when Lestrade bent to kiss him on the forehead. Sherlock rarely sleeps, but when he does permit his body the luxury of some rest, it can sometimes take all of Lestrade’s energy to wake him again.   
  
Before Sherlock can formulate a cutting reply, Lestrade’s mobile goes off.   
  
“Yeah?” he answers briskly. Sherlock sits up in bed, fully alert now. Lestrade waves him away and then plugs his other ear to better hear the caller. “Sal, you’re breaking up, I - Right. Yeah, I’ll be there right away. Ten minutes.”   
  
“What is it?” Sherlock demands, already halfway out of bed. Lestrade gets up from his desk and reaches for a relatively clean shirt--he’s only worn it once this week.   
  
“Nothing interesting,” he says at once, and Sherlock purses his lips. “Domestic that ended badly, looks like. You’d find it boring.”   
  
“No more boring than this damned cabin,” Sherlock mutters. Lestrade presses a kiss to his lover’s lightly-stubbled cheek before pulling on his suit jacket and picking up his mobile again.   
  
“Then go to the Infirmary and bother John.” Lestrade scrubs a hand through his hair. “I’ll see you later, yeah?”   
  
He leaves before Sherlock can reply, and hopes he won’t have to throw the younger man out of his crime scene later on.   
  
\-----   
  
Spaceships were giant sterile things, even when crammed stem to stern with refugees. Living in a vacuum solves a number of problems, it would seem, most illnesses among them.   
  
But the medical profession boomed after the escape from Earth, even under these conditions. Injuries started to outnumber illnesses once humanity took to the skies, and someone needed to treat them. They were rarely ever _minor_ injuries, too, and trauma surgeons were always in high-demand.   
  
Because if something goes wrong on this blasted ship, John Watson thinks wearily, it never goes only a _little_ wrong.   
  
Today already he’s had to treat two victims of a gravity field failure in Section 22, both of them children who came in with several broken bones and internal injuries. He’s also had a few instances of the cold--never could get rid of that one--and a case of hypothermia in one man who had gone outside to repair a section of the ship and got struck by a passing micrometeoroid for his efforts.   
  
In the time he has between patients, John pauses to wonder--as he does nearly every day--how the other ships are faring. Twenty of them had launched from the dying Earth’s surface a little over forty years ago, filled to bursting with refugees and supplies. One of them had tried to make a go of it on Mars, but the colony had failed in less than a decade. The other nineteen pointed toward the stars and never looked back. They traveled in solitude, figuring that humanity’s chances of survival were greater apart rather than together. Perhaps one of the ships would find a moon in the outer solar system capable of sustaining a colony. Perhaps another would develop the technology to travel faster than light and would actually be able to travel from star to star in search of habitable exoplanets.   
  
But for now, these ships are where humanity makes its stand, for the stars are just out of reach and they have more immediate concerns. From the radio contact London City has with the other ships, it seems that everyone’s situation is similar. The ships are too far apart now, decades after their launch, to be able to reach one another. In less than fifty years, even radio contact will be gone, and then London City will truly be on its own.   
  
It is comforting, then, to know that no one ship is better off than the others. They have the same illnesses, the same governments, and the same citizens. They have mouths to feed, injuries to treat, dead to bury, and children to birth.   
  
They are still humanity, even without an Earth.   
  
\-----   
  
The woman on Level 24 died quickly, and though that’s not much of a comfort, Lestrade clings to it anyway. She was shot in the back of the head and died in a pool of her own blood, sprawled face down on the floor of her cabin. It’s likely she didn’t even feel it, it happened so fast.   
  
“Fucking idiot, whoever did this,” Donovan spits, and as Lestrade kneels over the body, he is inclined to agree.   
  
Gunshot wounds are an infrequent occurrence on London City, as rare as guns themselves. It isn’t wise keeping weapons like that on this vessel, not when one ricochet could rip through a bulkhead and decompress an entire section of the ship before the hull repair bots could get to it. It’s too risky, and as a result weapons are highly regulated.   
  
On the bright side, it makes perpetrators easy to track down, with every gun out there being tightly tracked and monitored.   
  
But the bullet could just as easily have gone through the wall as it did this woman’s head, and no amount of gun control will have prevented that. Lestrade would sleep easier at night if every last bit of this ship’s arsenal was destroyed, but he knows that will never happen in his lifetime.   
  
“Her husband’s on the weapons registry, according to the database,” he says finally, pushing himself to his feet. “See if the bullet Molly digs out of her skull matches his gun. I’ll be at the Yard, working on the Dawson case. Let me know once you have something.”   
  
It amazes Lestrade that murders even occur on this ship, and with nearly as much frequency as they did back when London was an actual city on Earth. They almost never get away with it, murderers, and Lestrade enjoys a high level of success that he knows would have been impossible to maintain had he been on Earth, simply because he is operating in such a confined area here on London City. There is nowhere, literally, for suspects and perpetrators to run. On Earth, they had six billion entities to hide among, and an entire planet over which to flee.   
  
Here on their floating city, the population totals a little less than ten million, which is not nearly as immense as it sounds. There are thirty-five levels on their ship, from the engines all the way up to the main control room, and at any one time you were never more than a few hours from any other point on the ship. In his entire career, it’s never taken Lestrade and his team more than a week to track down a hiding suspect.   
  
He likes to think it’s because his team is brilliant and highly skilled. And the truth is, they are.   
  
“Detective Inspector.”   
  
They just have a little help sometimes, whether they ask for it or not.   
  
Lestrade pauses in the corridor he’s currently walking down, suppresses a sigh at the unwelcome voice, and says, “Yes?”   
  
The intercom on the wall crackles to life again.   
  
“I believe the man you’re looking for -”   
  
“It’s her husband,” Lestrade says briskly, cutting Mycroft Holmes off. “We know. We’re looking for him right now, and his gun. Shouldn’t take more -”   
  
“He’s on Level 8, Section 36. His gun appears to be on Level 10, Section 98.”   
  
“Yes, _thank you_ , Mr Holmes,” Lestrade says tightly. “We are capable, you know, of -”   
  
“Oh, I’m certain you are,” Mycroft says smoothly. “But why waste time when you can rely on your _numerous_ resources?”   
  
“Because the only reason you have any interest in me and my team is because I’m shagging your brother,” Lestrade snaps at the wall, causing two passersby to look at him oddly before continuing on, “and you know how much it annoys him when you interfere with my cases. Which I like to think is annoyance on my account, but we both know he’s just irritated you snatched the fun of solving a case from him. Now, if you’ll excuse me, I’m really not in the mood to get drawn into another one of your stupid head games today.   
  
“And stop fucking _following_ me.”   
  
\-----   
  
John comes off duty at 1400 hours and heads straight to Angelo’s on Level 15. He’s supposed to meet Sherlock there, as is their Thursday custom, and when he arrives he is surprised to find their usual table empty.   
  
“You’re late,” he says when Sherlock arrives at 1415, knowing that he’ll never get another chance to say that again in his lifetime. Sherlock rolls his eyes as Angelo brings over their usual orders.   
  
“I couldn’t find my phone.”   
  
“Sorry, what?”   
  
Sherlock glares. John shakes his head in bemusement, because Sherlock _never_ misplaces anything.   
  
“Next thing you’ll be telling me is that Mycroft relinquished control of this ship and fucked off to Bermuda.”   
  
That earns him a snort.   
  
“How’s Greg?”   
  
Sherlock scowls as he stabs at a piece of meat with his fork.   
  
“Why must you insist on asking that every time? Honestly. It’s hardly as though his condition changes drastically enough for you to constantly need to be checking in on it.”   
  
“I just - that’s what friends - you know, never mind. I’m sure I’ll hear about it at the pub on Friday. You’re all he talks about after the fourth pint. Is it true that you like it when he does that thing with his tongue and -”   
  
Sherlock’s eyes snap to his, blazing, and a slow flush starts to bloom at the base of his neck. John holds up a hand, struggling valiantly to hold back his laughter.   
  
“Sorry, sorry, that was cruel of me.” He turns his attention to his pasta. “I’m just joking. You know as well as I that the man’s tight-lipped to a fault, no matter how much liquor he’s had. Did you find it?”   
  
“What? Oh, the phone. Yes, it was in the kitchen. Did you fix your blog?’   
  
“Did I what? Why?”   
  
Sherlock sighs impatiently.   
  
“The details of our last case are blown _tremendously_ out of proportion. Take, for example, the chase down on Level 12. Now, I know you want to impress your readers, but really, John, did you have to -”   
  
“Yes, yes, _all right_ ,” John hisses, glancing furtively around the room. “So I... embellish a bit, here and there. It’s completely harmless. The readers love it, _and_ it makes you look good.”   
  
Sherlock smirks suddenly.   
  
“I suppose those are perks, yes, but not exactly the kind you’re after. Tell me, John, how often has your popularity as the writer of a well-known blog allowed you to get a leg over?”   
  
John feels himself flush.   
  
“Wanker,” he mutters, turning back to his food.   
  
“I suppose you would have to be, yes, in a situation of forced celibacy -”   
  
“Oh, _shut up.”_   
  
\---------------------   
  
The computer database calls them _environmental refugees_.   
  
It’s not a phrase that brings particularly haunting images to mind. In fact, it sounds positively tame when compared to other phrases that describe the causes of abrupt migrations, like _war-torn country_ or _natural disaster_. It’s almost deliberately vague and evasive, even, and the accompanying articles are clinical. Of all the mass extinction events in Earth’s history, only one of them was caused by an outside force. The others were a result of the planet itself trying to shake the thin film of life off its back--nothing at all like the depictions of friendly _Mother Earth_ humans so liked to cling to prior to the disaster.   
  
It was humanity’s collective stupidity, however, that brought about the planet’s most recent extinction event, and its collective innovation that saved them from falling victim to it. They were the reason that global temperatures rose, and why the ocean currents shut down. They were responsible for Europe’s mild climate disappearing in a perpetual flurry of snow and ice, for marine life vanishing amid a cloud of anaerobic bacteria, and for brutal summers that suffocated crops in the few areas left on Earth that could sustain them.   
  
They were _also_ responsible for having the means to escape the planet, and in under a decade had managed to build, stock, and launch twenty massive ships from the Earth’s surface, saving a good majority of the dwindling population. Most of those left behind had elected to stay voluntarily, and had not been heard from in thirty years.   
  
The computer database provides graphs and numbers to supplement these articles and the decades-old news reports, but Sherlock is so far removed from the event--both in time and space--that the images stir little emotion in him, except for contempt at the fact that he is the member of such an abysmally stupid species.   
  
Once, and only once, Lestrade spoke of Earth. It had been a bad night, that one, and made all the worse in retrospect because Sherlock didn’t have John at the time. If Lestrade is his anchor, then John is his compass, providing insight into emotions and reactions that Sherlock cannot fully grasp.   
  
But he had been alone on that night three years ago, alternating between confused and furious at the state Lestrade had managed to drink himself into, because he had promised-- _he had promised_ \--three months before that it wouldn’t happen again. Why would he promise that, if only it was going to be broken?     
  
It wasn’t an issue that Lestrade alone battled, though somehow that knowledge made it worse at the time. Alcoholism was more prevalent among the refugees than it was among the younger children-of-space, and Sherlock hated Lestrade at the time for being so _ordinary_ ; for submitting to such a common coping mechanism.   
  
_ It’s an addiction, Sherlock _ , John would tell him now. _He fights it, all the time. Just like you do with the drugs. He will always fight it. And it must be hard, you know, realising that once your generation is gone, no one will be left to remember Earth._   
  
Sherlock hadn’t had those words that night, though, and so he just sat stiffly on the sofa while Lestrade, in the chair across from him, nursed the evening’s fifth--sixth?--drink and finally uttered his first sentence of the day.   
  
“You’ve never felt rain, have you?”   
  
The floodgates opened after that first sentence. He spoke for nearly an hour, talked about rising seas and food shortages; of strange sunsets and precious, scarce water. He spoke of families who couldn’t feed their children and harsh winters that left scores dead. Felt like the planet was trying to shake them off her back, he said.   
  
And so they went.   
  
Sherlock had learned nothing new that night, nothing he hadn’t already discovered from the computer, but it had been frightening all the same to see his lover in such a state. And even then--hell, even to this _day_ \--Lestrade was careful with his food; conservative in his water usage. It was a habit formed in early childhood, and one he has been unable to break free from.   
  
Lestrade hasn’t touched a drink since that night.   
  
And he hasn’t spoken of Earth again.   
  
Sherlock shuts down his computer abruptly, having lost more time to the blasted thing today than he would care to admit. The cabin is too still without John, and too often Sherlock finds himself lost in the database instead of in his experiments, skimming articles as a means of distraction. He checks his watch restlessly, and realises that Lestrade will be coming off his shift soon.   
  
The melancholy lifts slightly, and Sherlock abruptly leaves the too-quiet cabin.   
  
\-----   
  
Lestrade wraps the Dawson case a little after 1100 hours and then spends the remainder of his duty shift with the murder victim found on Level 24. Jennifer Wilson’s her name, and they find a motive before they find her husband--it turns out she was a serial adulterer, and that their marriage was rocky to begin with. The case is textbook.   
  
That doesn’t make it any easier to wrap, however. It still isn’t finished by the time Lestrade goes off duty, leaving Jennifer Wilson’s husband--widower--sweating it out in a room with Sally Donovan and steadfastly denying everything. The test results from his gun will be back by tomorrow morning, and after that they won’t really need his full cooperation.   
  
It’d have been nice to get a confession before that, though, but the man has been pleading innocence from the start. It’s going to be a long night for Sally, Lestrade feels.   
  
He heads back to his own cabin, and is surprised to find Sherlock there.   
  
“John’s back on duty,” he says immediately when Lestrade enters. Lestrade suppresses a sigh. He’d been hoping for a bit of peace, something he’s not had in nearly a week and had been expecting to have tonight. Thursday nights are for John and Sherlock alone, for which he is--usually--distinctly grateful.   
  
“Oh?” he says, not particularly caring, and sheds his jacket.   
  
“Yes, something about a grav field failure on Level 12 again. He’s the only one equipped to handle such injuries.”   
  
“How inconvenient for you.”   
  
“Yes,” Sherlock says, sounding put out. “You’ll do in the meantime, though.”   
  
“Got a call from your brother today,” Lestrade says testily, ignoring the last comment--or perhaps spurred on by it. “He solved my case.”   
  
“Good,” Sherlock says absently, tending to something questionable that he’s cooking in Lestrade’s small kitchen.   
  
“No, not _good_ ,” Lestrade snaps. “Irritating. Annoying. Meddling. A fucking _pain in the arse_.”   
  
“Don’t you want it solved?” Sherlock sounds honestly perplexed, which angers Lestrade all the more.   
  
“Yes,” he hisses, “and it would have been, too! I do have a team, you know. A whole bloody team, and they’re goddamn useless because Mycroft enjoys having a bloody power trip at their expense. But you know, Sherlock, _my life is not for Mycroft’s amusement._ I am not here to be used against you, nor against Mycroft. _I am tired of being a pawn in your fucking head games.”_   
  
Sherlock stares at him, blankly, and Lestrade goes on.   
  
“I’m tired of being caught between you and Mycroft. You two are so _fucking_ eager to one-up each other that you drag everyone else in your lives along for the ride. And I can tell you right now, it is _not_ enjoyable.”   
  
There is a pause. Sherlock’s lips thin in anger, and he draws himself up stiffly.   
  
“If you are so _tired_ ,” Sherlock says tightly, his words dripping with acid, “then why don’t you _leave?_ I would hardly want to _impose_ my life on someone who despises it so much.”   
  
Lestrade deflates suddenly, growing bone-weary in a matter of seconds. He knows how their relationship looks to the outside world--to those who know about it, at least. More than once he’s received pitying glances and murmured consolations on pub nights when Sherlock shows up, only to steal John away on important business.   
  
The others don’t trust Sherlock. But they don’t really know him, and Lestrade’s never, not for a moment, doubted Sherlock’s sincerity.    
  
And, up until now, he never had realised that perhaps Sherlock doubted _his_.   
  
“Lad, if leaving was an option,” Lestrade says quietly, “don’t you think I’d have done that already? Look, don’t be daft. I’m not going anywhere.”   
  
He sighs and sits heavily on the sofa.   
  
“Anyway, it’s not _you_ I want gone, believe me. I just wish there was a way to make your brother back the hell off. But how do you tell a _ship_ to go fuck itself?”   
  
The corner of Sherlock’s mouth twitches in repressed amusement.   
  
“I’m sure he heard,” he points out.   
  
Given Mycroft’s irritating omnipresence, he’s probably right. Lestrade snorts.   
  
“Then he’d better listen to this as well,” Lestrade says. He makes a rude gesture at the ceiling with his hand, and then accidentally meets Sherlock’s gaze.   
  
Two days of sleeplessness crash over Lestrade. He dissolves into uncontrollable laughter. He even gets a few chuckles out of his normally reserved lover, and reaches out for Sherlock’s hand. He tugs until Sherlock is sprawled on the sofa with him, and pulls Sherlock’s legs up until they are resting across his lap.   
  
“Working on experiments today?” he remarks, giving Sherlock’s earlobe a tug. Sherlock winces and glares half-heartedly at him. “You’ve some ink there. Writing some notes down, I take it. Still don’t know why you bother when you have the entire computer system at your disposal.”   
  
“I hardly need a technology lesson from the man who can’t figure how half the time how to make calls to other cabins,” Sherlock shoots back, but it lacks true heat. “And you know I prefer not to leave sensitive information floating around in what amounts to my brother’s brain.”   
  
Sherlock reclines suddenly, and takes Lestrade with him. He sprawls on top of Sherlock, burying one hand in his hair and bracing the other on the sofa for support. Sherlock smirks and gives a slow twist of his hips; Lestrade groans.   
  
“Look, kid,” he mutters, lowering his head to trail delicate kisses along Sherlock’s jaw, “whatever you have in mind, _stop it_. I’m too damn old for the sofa and you know it.”   
  
Sherlock pushes himself up on his elbows and captures Lestrade’s lips in a hungry kiss.   
  
“Prove it.”   
  
\------   
  
Lestrade is a silhouette by the porthole--barely that, even. His presence by the window is noticeable only because of the lit cigarette that he holds between his fingers. Its acrid smell has not reached Sherlock thanks to the ship’s ventilation system, but its faint glow is the equivalent of a bright beacon in the complete darkness of the room.   
  
Sherlock searches among the blankets for his mobile, discarded in their earlier haste. His squints at the readout, eyes watering, and then tosses the device in the direction of the bedside table with a frustrated groan. It is far too early.   
  
“What is it you see out there?”   
  
It’s not an uncommon occurrence, this--waking to find Lestrade staring out the porthole in the middle of the night, almost longingly.   
  
Lestrade snorts.   
  
“Nothing that would interest you.”   
  
Sherlock slides from the bed, suppressing a hiss as his bare feet come into contact with the cold floor, and steals across the room until he is standing behind Lestrade, back-to-chest, savouring the warmth of his lover’s body.   
  
“Try me,” he murmurs against the shell of Lestrade’s ear.   
  
Lestrade gestures vaguely at the porthole and the stars beyond.   
  
“It all looks so calm,” he says, “doesn’t it? A million points of light, shining in the dark. Almost makes you forget that each one is a star, and we can see it only because it’s burning up from the inside out. That is, if it’s even still alive anymore. It could have blown itself to pieces centuries ago, and we wouldn’t know for a thousand more years. Ten thousand.”   
  
He takes another draw on his cigarette before Sherlock steals it from him. Lestrade doesn’t even protest as Sherlock smokes what is left and then disposes of it with a flick of his fingers. He goes on, absently.   
  
“And the dark that seems so peaceful is really a vacuum, and we’d die in it in under a minute.” Lestrade sighs heavily through his nose. “It’s hard to remember all that when it looks like this, though. Y’almost don’t want to think about the fact that something so beautiful--and so close--could be so deadly.”   
  
“You make it sound like the universe is out to get us,” Sherlock says in some amusement. Lestrade shakes his head slowly.   
  
“No. It just doesn’t care whether we survive or not.”   
  
Sherlock lowers his hands to Lestrade’s hips; presses lips to the back of his neck.   
  
“You think too much,” he says in a low voice, bringing a decisive end to the conversation. “Come on. Back to bed.”   
  
  
Lestrade has a mid-afternoon shift the following day and sleeps almost until noon. Sherlock leaves his bed around mid-morning, gathering clothes that had been hastily discarded the night before and putting them back on. He departs for his own cabin just as Lestrade is rousing-- _left some eyes in the microwave; best not to let John discover them_ \--and is halfway through an experiment when his cabin lights go out.   
  
Suppressing an irritated sigh, Sherlock reaches for a torch that he keeps in his desk drawer.   
  
Before he can grab it, however, the deck disappears out from under his feet, and he goes sprawling.   
  
A moment later, alarms start going off.


	2. Chapter 2

John has been up for thirty-six hours when the ship gives a violent lurch, and at first he thinks it’s a trick of his overworked mind.

But he catches himself against a table and notices that half his staff has gone flying as well, along with equipment and a couple of patients.

Not a figment of his imagination after all, then.

He helps a little girl back onto her bed and is reaching out to give Sarah a hand up when the ship jolts for a second time, and they all go down again.

And then the lights go out.

\-------

When the ship shudders and jerks, Lestrade is back in his cabin on a quick dinner break. Caught off-guard, he goes down hard and smacks his head against the sharp edge of a table in the process. He doesn’t lose consciousness, but for some moments he sits there, dazed, with blood dripping into his eyes from the gash on his forehead.

The pain subsides enough after a couple of minutes that his mind begins to clear, and Lestrade pushes himself to his feet. The main lights have gone out, and have been replaced only with dim emergency lighting that runs along the wall at his feet and at eye-level. The cabin has been thrown into shadows, and he navigates gingerly over to the door.

It doesn’t open.

_ “Bugger,”  _ Lestrade hisses in agitation. He throws his entire weight against it, but it still won’t budge.

It’s then that he realises that the room is too quiet, and the floor beneath his feet too still.

The engines have stopped.

It takes Lestrade a full ten minutes to bring his intercom system back online, and even then it’s only partially working. He can’t call specific cabins, only general parts of the ship. A further twenty minutes pass before he reaches the correct room in Section 2--the auxiliary control room.

However, he expects Smith to answer and is surprised when one of his own people takes the call instead.

“Anderson?” he blurts in surprise as the man’s voice comes over the intercom. “What are you doing up there?”

“Running some tests for our last case, sir. Or I _was_ , at least,” Anderson says wearily. “The computers up here are more powerful than at the Yard, you know that.”

“Where’s Smith?”

The pause is ominous.

“Dead. Smashed his head in when the ship got hit with... whatever it is that hit us. It’s just me up here, now.”

"Are you all right?"

"Fine, yeah. You?"

"Door's jammed shut," Lestrade says irritably. "Otherwise, yeah, fine down here as well. Can you tell what's going on?"

“Not really. Ship’s dead, sir,” Anderson says.

“And what exactly does that mean?” Lestrade demands.

“It means that somehow Protocol 47 got activated, and that everything’s shut down.”

Lestrade sucks in a breath. Protocol 47 was the ship’s last line of defense in a disaster. It effectively shut down the ship and sealed off the damaged areas from one another so that the problem - whatever it was - couldn’t spread.

“Can you see what activated it?” he asks.

He can almost feel Anderson shaking his head. “Not unless we can get the sensors back online. But I’m not an engineer, sir.”

“No,” Lestrade agrees, “but you’re the closest thing we have to one right now, and one of the smartest men I know. See what you can do. And is there any word from the main control room?”

He really means _Is there any word from Mycroft?_ Anderson pauses too long before giving his answer.

“It’s gone dark, sir, all of it. They’re -”

“- dead up there, most likely, or severely compromised,” Lestrade finishes. “Either way, we’ll be getting no help from them. We’re on our own, now.”

\---------------

Sherlock wakes to find that the world has gone vertical, and it takes him a moment to realise that he’s lying on the floor of his cabin. Gingerly, he pushes himself into a sitting position. He touches his forehead, and his hand comes away bloody. A quick inspection reveals also a busted lip and sprained wrist, all from him trying to break his fall as the ship lurched. All around the cabin, his things are scattered, and when he tries the door he finds that it won’t respond to his commands.

_ Dammit _ .

The intercom crackles to life.

“Hello, Sherlock.”

The voice is lilting and male, but otherwise unremarkable.

“What?” he groans irritably. “Who is this?”

“You don’t remember? Pity, pity. Did I really make so little of an impression?”

Sherlock says nothing, but his heart has begun to knock wildly against his ribcage. It’s been months since they last heard from Jim Moriarty, and an emotion he doesn’t want to name tugs at his throat. He should be feeling terror; trepidation. In truth, the chaos that is his mind has snapped into order, and the voice on the intercom chases away the white noise that claws continuously at his brain, day in and day out.

His mind is clear and sharp, focused for the first time since the bombs last April, and it is _glorious_.

“Moriarty, I presume,” he says, as calmly as he can manage. It isn’t much of a struggle. “What is it you want this time?”

“All in good time, my dear. I fear you’ve rather more important things to be dealing with at the moment.”

“Like what?”

“Your cabin there is leaking air like a _sieve_ ; I expect that is a little more important right now. And a bit more fun, yes?”

Sherlock glances around the cabin, but can see no sign of a breach.

“Oh, you can’t see them, my dear. What would be the point of that?” The man on the intercom giggles. “Micrometeoroids. Useful things.”

“This is your doing?”

“Shh, shh, darling, don’t speak, you’ll _waste_ precious air. No, not exactly my doing. I simply saw an opportunity and I took advantage of it.”

“What is it you want?”

“I _want_ ,” the man drawls, “to see you dance. Now jump to it, sweet Sherlock, and if you complete this task successfully, I’ve another puzzle waiting for you. If you don’t--well, death cures boredom rather well, doesn’t it?”

And then he is gone, before Sherlock can even begin to form a reply.

\----------------

An hour later, Lestrade has shed his outer jacket and rolled up his sleeves as the temperature in his cabin begins to climb. He’s had no luck opening his damaged door, nor with reaching anyone of importance. Every time he reaches out through the intercom, blind, to someone else, it is the same story. All over the ship, people are trapped in their cabins or the common areas, with no way of reaching the control room.

“Sir,” Anderson says, the intercom flaring to life and causing Lestrade to start, “are you still in there?”

“Talk to me, Dan.”

“Near as I can tell, we’ve got hull breaches.”

Lestrade blinks. “Breaches?”

“Yeah. Seems like we passed through a cloud of micrometeoroids. I’ve only got partial sensors, but it’s enough. These breaches are all over the ship. That’s why the seals activated.”

“Okay. And...”

“And if we can seal all the breaches, the ship will automatically recognise that the danger has passed and relinquish control again.”

Lestrade sighs heavily. “Right. What parts of the ship are affected?”

There is a lengthy pause, and Lestrade curses under his breath. _Of course_. That’s why his door had refused to open--it wasn’t damaged at all.

It had sealed itself shut.

“ _Shit.”_

“There are twelve breaches in your cabin alone,” Anderson says finally. “You’re leaking oxygen, sir.”

“How long?”

“Six hours,” Anderson says, “but you’ll feel the effects long before then.”

Lestrade, no stranger to the dangers of space, nods. “Yeah, I know. Right, start getting the word out to as many people as you can reach. They need to find these breaches and seal them. Tell them to use whatever materials they have available to them. Are you all right?”

“Yeah, I’m clear up here. The Infirmary is safe, too, as is the Engine Room. We’ve got damage to nearly all the greenhouses, though, as well as to our water reserves. The Yard was hit hardest--we’ve got at least twenty-seven offices completely exposed to space, and we’ve lost some people up there already.”

The question Lestrade doesn’t want to ask but needs to know tugs at his tongue. Anderson answers it before Lestrade can figure out how to delicately frame it.

“All of the cabins on Level 2, Section 21 have been compromised,” he says quietly. “Not as badly as the Yard, but everyone there has about five hours to fix the breaches or find a way to break the seals on their doors. Otherwise...”

Lestrade nods to himself and tries not to think of Sherlock.

“Thank you, Daniel. Get the word out to them quick as you can, yeah? And keep working on trying to override the protocol.” Lestrade swipes the back of his hand across his forehead. “Any idea why it’s so hot in here?”

“Environmental controls are on the fritz,” Anderson says.

“Shouldn’t that make things colder?”

“It will, as time goes on. Right now they can’t figure out what the temperature truly is and are overcompensating. Eventually, they’ll shut down, and the temperature will drop quickly after that.”

“Great,” Lestrade mutters. “How’s oxygen looking, overall?”

There is a pause.

“If none of the breaches are fixed, the last of the affected areas will drain in twelve hours,” he says at last. “Those in the sealed-off portions will use up the rest of the air reserves in six months, unless we can get the oxygen system back online. But food and water will run out completely in three, so it might not matter.”

“The only way we can possibly survive this,” Lestrade says, more to himself than Anderson, “is to find and seal every last breach, so the computer will deactivate the protocol.”

He tosses aside the tool he had been using on the door and rubs a hand across his face in frustration.

“Damn, blast, and _hell_.”

\---------------

The Infirmary is in chaos.

“Get this man into surgery, now!” John bellows. Sarah wheels him away, and John moves to the next cot. His next patient is a woman, burns covering almost the entirety of her body, and her skin peels off when he touches her arm. She’s unconscious, pulse faint to the point of nonexistence, and he grimly marks a black “X” on her forehead before moving on.

It isn’t long before all their beds are occupied and the cots full, spilling out into the corridor as they try to accommodate all the patients. They have been sealed off from the rest of the ship, along with Sections 100 through 197, cabins that are mostly comprised of families. The intercom still works, though, and cries for help are coming in from all over, though there’s little they can do about them all.

“John.”

Someone touches his shoulder, and he whirls.

“Oh, Molly,” he sighs. “Sorry, look, I know it hurts, but I’ve got to see to these other patients first -”

“No,’ Molly Hooper says quickly, interrupting him. She had been in the Infirmary when the disaster struck, John treating a sprained ankle she had got from falling down a short flight of stairs. “I want to help. Tell me what to do.”

John blinks at her. “I don’t think that’s a good -”

“Tell me what to do,” she repeats, firm. “I’d rather not see any more of these people pass through my morgue.”

He hesitates only a moment. Then, he hands her a burn repair kit, and sets her to work treating non-fatal injuries.

\-----------------

The first thing Sherlock does is call Lestrade.

Or try, at least. The intercom is finicky at best, and though he can pin down Section 34, he keeps getting bounced to different cabins, none of which are the one he wants.

On his tenth try, though, the familiar West Country clip says, “Yes, what is it?”

“Do sound more grateful, Lestrade, I’m only going to save your life.”

There is a stunned silence.

“Sherlock,” Lestrade says finally, concern evident in his voice, “are - well -”

“Yes, I’m fine,” Sherlock says briskly. “Your cabin has been compromised, I take it.”

“As has yours.”

“Yes. So I need you to find some sugar.”

“What?”

Sherlock makes an impatient noise. Was he really going to have to spell it all out?

“Or salt, or pepper. Anything made of small grains. Quickly, I haven’t the time nor the air to spend arguing with you.”

As he speaks, he goes over to his cabin’s small kitchenette and pulls out John’s container of sugar.

“Found it yet?”

“Salt will do, you said?”

“Fine,” Sherlock says briskly. He takes a handful of sugar and says, “Throw it in the air.”

“I assume there’s a reason for that.”

Sherlock tosses the sugar towards the ceiling. Most of the grains rain down again immediately around his head, but a few start to drift toward the right side of the room before falling to the ground. He repeats the process, tracking the grains until a cloud of them disappear through the wall just next to his bed.

“Yes,” he says, brushing his fingers along the wall even though he knows he won’t be able to feel the micro-fissures. “The particles will be drawn to wherever the breaches are in your room and sucked out into space. It will help you figure out what you need to seal. If it doesn’t work at first, move to a different part of your cabin and try again.”

There comes a moment of silence.

“Looks like they’re near the wall by my office, but I can’t see anything.”

“You won’t be able to. Micrometeoroids, remember?” Sherlock says impatiently. “Find something to spread on the wall, anything that might be able to cover the holes.”

He ducks into his lab and emerges with a gelatinous substance he had been conducting experiments on just yesterday. The experiments had failed, but the new substance that resulted from them proved to be particularly adhesive. He starts to spread it along his wall.

“All I’ve got is toffee pudding.”

“That might do. Did you make it?”

“What does that have to do with anything?” Lestrade asks, managing to sound indignant even in the midst of this crisis.

Sherlock smirks to himself. “Because if you did, it just might work. _That_ could stick to anything.”

“Oh, shut it, you,” Lestrade says, sounding slightly amused. “You’re no help, you know that?”

“So I’ve been told. There’s a can of sealant in your desk, use that. It should be sufficient.”

“Why is there a can of sealant in my desk?”

“I was conducting an experiment. Are you going to argue with me, or are you going to let me save your life?”

“Can’t I do both?” There is a pause and a rustling sound. “Right, found it. Remind me to never let you in this cabin again, by the way.”

“Duly noted.”

As they descend into silence once again, Sherlock hears a soft _click_ , and turns to see his door sliding open of its own accord.

“First test passed, it would seem,” he murmurs to himself.

“What was that?”

“Nothing,” Sherlock says. “It’s just that I was successful. My cabin’s opened.”

“Get out of there, then, quick as you can,” Lestrade says quietly. “Get somewhere safe and lie low, do you hear me?”

“Yes,” Sherlock lies, and dashes from the cabin before he hears Lestrade’s reply.

The corridor outside is silent and dark. He can hear banging around the corner, fists raining against a door as the occupants inside try--and fail--to get out.

A display on the wall to his right lights up, and Sherlock turns.

_ Engine Room _ , it says, and then, _You have ten minutes, Sherlock Holmes._

He runs.

**Notes for the Chapter:**

> **Author's Notes:** Sherlock's solution for finding the microbreaches is a modified version of a similar situation from _Star Trek: Enterprise_ 's "Shuttlepod One."  
> 


	3. Chapter 3

  
Two hours since the disaster, and they have had no luck in getting out to the rest of the ship.

John hasn’t spared it much thought, because he has an Infirmary full to bursting with casualties and half his medical staff was in other parts of the ship when the accident occurred. They are understaffed and overworked, and John hasn’t seen injuries like this since---

\--well, not since medical school. Never in practice, certainly.

“Someone finally managed to get through to one of the control rooms,” Sarah Sawyer tells him between surgeries as they convene in his office. “There are hull breaches all over the ship, which is why it’s been sealed off. Old safety mechanism. There’s no override, except for fixing the breaches.”

“Give me numbers, Sarah,” he says impatiently.

She gives him food, water, and air estimates for their section of the ship, and then says, “What should we do?”

“You’re asking me?” he snorts, but she looks grave.

“Yes,” she says simply. “You’re the highest-ranking officer here, and you have the most experience. People are going to need some sort of leader and some sort of organization, or we’ll never get out of this alive.”

“I’m a captain only in title, you _know_ that,” he says. Their army is one in name only, and has never seen combat or a battlefield--bar a few of the oldest members, who had been young and inexperienced when the last war on Earth ended and humanity took to the skies.

“We have only two orderlies. We need more if we’re going to get to all of these patients in time. I want to pull some of the least injured civilians and put them to work,” Sarah says briskly, ignoring his protest. “Everyone else who’s not too injured for a bed should get to work trying to break the seals so we can get aid to the rest of the ship. Agreed?”

He nods.

“Good. I’ll tell them the order came from you.”

She makes to leave, but just then the intercom by John’s desk comes to life.

“Hello?”

It is a young woman’s voice, weak and raspy.

“Yes, hello?” John says. “Who is this?”

“Is - is anyone there?”

“This is the Infirmary,” John says impatiently. “Look, this is a very important line and I need to have it cleared -”

“I need help.”

John and Sarah exchange glances.

“What’s wrong?” John asks.

“I need - I need help.”

“What’s _happened?_ You need to tell us.”

“I - I can’t move. I’m trapped. I think... God, I think my leg is broken. And my son... Eric, he was with me when the beam collapsed, and he’s not responding. Oh, God... he’s only twelve. Eric?”

“Where are you?” John demands, as much out of urgency as it is out his desire to not have to hear a mother pleading for her child to answer her.

“Section 112. Level 2. Cabin... shit. Cabin, um.”

She sounds dazed and desperate, her voice wavering with every word.

“Take a deep breath,” John orders briskly. “We’ll send someone to find you, I promise. But you need to breathe and think. What’s your name?”

“Martha,” she manages.

“Right, Martha, I’m John. Now, can you tell me what cabin you’re in, please?” 

He speaks in as level a voice as he can manage, hoping to keep her calm. After some more minutes of coaxing, she’s able to tell him where she is, and he assures her that help is on the way.

“I know what you’re thinking,” Sarah says immediately when he cuts the line. “And we can’t spare you.”

“You’re going to have to,” John says, reaching for a bag and beginning to pack some medical supplies--just a few, enough to hold two people together long enough to get them proper care. “You and I are the only ones in this section of the ship who are equipped to deal with such injuries. It shouldn’t take that long. I’ll have to go through the tunnels to reach them, that’s probably fastest and they’re hopefully deserted. I’ll be back in a couple of hours. You and Molly can handle things until then.”

“You can’t know that.”

“No,” John agrees, slinging the bag over his shoulder and going over to a secure lockbox set into the wall. He keys in the code and pulls out his gun, which he slides into his belt for lack of any better options. “But I don’t see how we have any other choice. _I’ll be back_. Promise.”

\----------

Two and a half hours have passed since the accident, near as Lestrade can tell. It’s solely guesswork, as he can’t locate his watch and the computer’s clocks have all gone offline, the ship channeling all non-essential power into the most vital areas. But he hasn’t started to feel short of breath yet, and therefore knows it can’t have been more than four.

The temperature has started to drop, just as Anderson predicted, and Lestrade puts on the jacket he had shed earlier. The chill is just beginning to tinge the air, and he can feel it starting to prick at his nose and the ends of his fingers. It sharpens his mind after the muggy heat; focuses his thoughts. He begins to work more quickly in an effort to keep warm.

Finally, his efforts pay off. There is an audible _click_ and then what sounds like a sigh as the door unseals itself, and Lestrade lets out a breath.

He has kept an open communications line with the auxiliary control room so as not to lose contact with Anderson, and he breathes, “Did it, Daniel.”

“Oh, thank God.” Anderson doesn’t even try to conceal his relief. “Now what, sir?”

“You stay where you are and keep up your calling. I’ll come to you, soon as I can. Keep people calm; keep them focused and working. The more breaches we seal, the more chance we have of getting the ship back and people out of his alive.” Lestrade goes over to the door and shoves it open fully. “See if you can find others near you, or in the vicinity of the other control rooms. We need to find a way to override the ship’s security system, if all else fails.”

“You’re going after him, aren’t you.” It’s more a statement than a question.

_ I wish _ .

“Much as I may want to,” Lestrade admits, “no. I’m going to try to get into the main control room.”

There is a heavy pause.

“I don’t suppose there’s anything I can say to dissuade you,” Anderson says in resignation. “But sir, that could very well be suicide. We don’t know what happened to Mycroft Holmes and his staff.”

“I know. But if we want to take this ship back, our only hope is that room. The auxiliary control rooms just don’t have the power, nor the technology that we need. All they can do is delay the inevitable, so keep it up, Daniel. Make sure people are fixing those breaches, and tell anyone who’s mobile to start making for the MCR. The more manpower we have, the better.”

“People are gonna start dying in about three hours,” Anderson says at last, silently conceding to Lestrade’s decision.

Lestrade nods to himself.

“Then I’ll just have to work quickly. Good luck, Daniel.”

“And to you, sir.”

\-----------

The tunnel is dark.

John feels as though _dark_ is an understatement, though, as he climbs down a ladder through the innards of the ship. These tunnels that snake through the walls and between the floors of their ship provide repairmen with access to the delicate circuitry that keep their floating city running. The tunnels also, in a pinch, provide a way of traveling between levels and sections if the lifts are down. Usually these tunnels are well-lit, but with the ship running on emergency power, the lights aren’t considered essential.

He descends through the ship with his bag slung over his back, his progress hampered by the fact that he can’t see the next rung for his hand or foot; he has to feel each and every one of them out. Mentally, he keeps tally of how many levels he has passed through. It’s eight from the Infirmary to Level 2; he is just over halfway there.

And then he will have to feel his way along a tunnel to Martha’s section, hopefully without encountering any obstacles that he won’t be able to see ahead of time.

His foot steps off a rung and comes to rest on solid ground--he’s made it. There’s nowhere else to descend from here. Level 1 is devoted exclusively to the engine room, accessible only to a select number of personnel. There is only one way in, and it’s not here.

John adjusts his bag, turns to his right, and begins to walk. He started out in Section 164 on Level 10, which is where the Infirmary is located. The tight corridor he’s walking down now is actually set between two very thick walls and runs behind all of the cabins on this level. Their outer walls are to his left; on his right, there are six feet of solid metal, and then a vacuum.

He shivers, and walks on.

The boundary between sections is marked by numbers carved deep into the walls, enough so that they are discernible by touch alone. John runs his hand over _138_ , surmises that he’s been walking for twenty minutes, and sighs.

Halfway there.

There is a _click_ behind him, and John whirls.

_ Stupid, stupid _ . It’s not like he can see anything, anyway. He presses his back against a wall, exposing as little of himself to open air as is possible, and holds his breath.

There comes another _click_ , but this time to his left, and from further down the cramped corridor. A beam of light catches him in the face, and though it is weak, John flinches anyway. His eyes have become accustomed to the unending darkness, and the light burns his eyes.

Against his eyelids, he sees another spot of illumination to his right and, squinting, he ventures a look.

Soft beams of light are flashing at him from up and down the corridor, coming from at least five different sources, and for a moment he is hopeful. But then he realises that they are coming from too close to the ground to be torches held by people, and his heart sinks.

“Sorry, Johnny-boy,” a voice says suddenly, and John starts violently. “Martha won’t be getting your help anytime soon--not that she would have, anyway. I made sure of _that_.”

John feels as though the floor has been ripped out from beneath his feet, and his stomach bottoms out as though he is plummeting through open air. He hasn’t heard that voice in close to a year--and yet, there is no mistaking it.

“Moriarty,” John hisses, trying to mentally find his footing again. The _clicking_ sounds are getting louder, and finally the source of the light comes into view--one of the sources, at least. It _beeps_ , pauses, and flashes its light full in John’s face. “What’s going on?”

“Oh, Johnny, I’m afraid I’ve been a bit _naughty_. How terrible for you.”

“Yeah, spare me the speeches, what’s that _thing_ doing?”

“He’s reading you,” Moriarty says gleefully, and it takes John a moment, but eventually he realises that he’s looking at one of the ship’s emergency repair bots. Small, silver, and nimble, they are mostly kept in the storage bays, except when performing minor maintenance or repairs on the ship’s hull. “He’s _assessing_ your condition. Isn’t that sweet?”

“What do you want?” John growls, testily, because he’s not liking the way this robot is considering him and there are dozens of patients in his Infirmary who could use his attention. Instead, he’s out here on this wild chase to help a patient who may never have existed in the first place -

_ “I  _ don’t want anything. Not from you directly, at least. I am hoping your cabinmate will provide me with some delightful entertainment, and you may be a contributing factor to that end. But I wouldn’t worry too much about my motives at the moment.”

“And why not?” John snaps. The bot _whirs_ , and then inches closer.

_ What the devil? _

“Because, Johnny, our little friend has scanned you, and decided that you’re in need of some... _repair_.”

“Some _what?”_

“Humans,” Moriarty crows. “You all are so full of holes, full of _orifices_. So messy and inelegant. Yes, my robots are going to _fix_ you, Johnny-boy.”

“What the hell are you talking about?” John hisses. A robot inches closer, and he takes a step back. _“You humans,_ what the hell’s that supposed to mean? _You’re_ human. I saw you! Last year, at the pool, when you strapped a bomb to me, remember?”

“Did I?’ Moriarty says gleefully. “Or were you seeing only what you wanted to see? Or what _I_ wanted you to see? Maybe that _was_ me, but it just happens that I’ve made tremendous strides since then. You’ll never know, Johnny, I’m afraid. Time, as they say, is _up_.”

The line cuts out, and the repair bots start to advance.

\-----------

Sherlock makes it to the engine room and finds that it hasn’t been sealed off.

No microbreaches for him to fix, then.

“No, no, of course not,” a voice filters through the room. “Where would the fun be in that?”

“Why have you decided to speak to me in your own voice this time?” Sherlock asks as he goes over to the nearest computer panel. He touches a few of the controls; the panel doesn’t respond. The engines have stopped running, too, though that has nothing to help lower the oppressive temperature. This room always ran hot. “Thought you didn’t like to do your own _dirty work_.”

“It’s foolish to try to distract me, Sherlock, surely you’ve realized that by now. It just _won’t work_. Now, go over to the computer screen two paces to the left--ah. There’s a good boy.”

The voice slides silkily up Sherlock’s spine, and he shivers.

“Turn it on,” Moriarty orders, and Sherlock does so. The screen flares to life, and after a moment he realises that he’s looking at a schematic of the ship. It is a live blueprint, and the damaged areas are marked in red. Here and there, green dots move across the screen, and Sherlock finds that if he touches them with a fingertip, a name appears. “Oh, very good, my dear, you catch on quite _quickly_.”

“It’s the ship, obvious, and clearly it shows the movements of most of its inhabitants,” Sherlock says impatiently. “But why should I care?”

“I don’t expect that you do; not as yet. So let’s make things _interesting_ , shall we? Isn’t that what you’re always looking to do?”

Sherlock opens his mouth to argue that what he finds _interesting_ probably differs from Moriarty’s definition of the word, but then--for once--thinks better of it. Partly because it’s untrue.

They are more alike than Sherlock permits himself to admit, most days.

“In ten hours, everyone in the affected areas of the ship will be dead,” Moriarty intones while Sherlock watches the screen. “In six months, everyone who survives this particular incident will also be dead. But you don’t care about them, do you? So let’s make it a bit more... _interesting._ In three hours, your _blundering_ lover will stumble head-long into his own death, while at the same time, what’s left of John Watson will be discovered by a repair crew trying to break through to the lower levels.”

Sherlock’s eyes dart over the screen, frantic, but the green dots bleed together and he has difficulty distinguishing one from another. He starts tapping them at random, but the names that pop up are unfamiliar.

“You have three hours,” Moriarty murmurs, “and you can only save one.

“So you have a choice to make, Sherlock Holmes: your friend... or your lover?”

\-----------

It’s been almost a year since John’s had to fire the weapon, but his skills haven’t suffered for it.

He takes out three of the robots before they get to within ten feet of him, his aim sure and steady. He manages to avoid puncturing the outer bulkhead with the bullets. If they go through the robot,  then they end up buried in the inner wal l.

It takes three bullets for John to realise the flaw in his plan.

He only has so many bullets. London City has hundreds of these miniature repair bots for the hull alone, and scores of others that are used in other parts of the ship. All in all, John would estimate that near one thousand robots inhabit the ship.

And if Moriarty has got to them all...

John puts the gun back into his belt and swings up onto the ladder, hauling himself up to Level 3 and shutting the hatch behind him. It won’t stop the robots for long, as they can scale walls and cut through the ship’s hull with small laser beams, but maybe it will buy him some time to think.

He needs a new plan, and quickly.

\---------

Lestrade lives only two levels away from the Yard, and once he’s free of his cabin, that’s where he goes first.

Part of him hopes that he’ll see Sherlock there, for he doesn’t believe for a second that his lover is lying low somewhere, like he promised. But the Yard is deserted, the portions that aren’t exposed to space having been evacuated.

Lestrade’s own office was spared, and he quickly begins to collect supplies, anything that he can carry on him. He pockets a penknife and goes into a locked drawer for a gun he’s not supposed to have. Sherlock had got his hands on it back in April, after his encounter with Moriarty at the pool. _For protection_ , he’d said, though Lestrade has never had need to fire a weapon outside of training courses. He’d held onto it anyway, unease tugging at the back of his mind, and now he’s distinctly grateful for it.

The big question, the one that he has refused to think about too much since this whole ordeal began, is _where’s Mycroft?_ No one has heard from him, and there has been no evidence of his activity, which frightens Lestrade more than he cares to admit. But as he jogs down empty and dim corridors, searching for any evidence of life, he can’t keep his mind away from the question much longer.

Mycroft, quite literally, _is_ the ship. He’s Sherlock’s brother--and a Holmes--in name only, for what he is today is nothing close to the child Violet Holmes gave birth to all those decades ago. Years of research, development, and experiments conducted by men of Mycroft’s choosing have transformed him into a human with the ability to interface with the ship; with enough cybernetic components to actually physically fuse with their floating home. He hasn’t left the main control room in close to a decade, Lestrade knows. He has no need to.

From his vantage point, Mycroft is aware of nearly every movement, every sneeze, every _cough_ that happens on the ship. He can manually control the environmental systems, the engines, the food supply--anything he wishes. Security cameras mounted in every corner of every level allow him to see everything he wishes to see. He knows where the ship needs maintenance, and what has been damaged and what needs to be repaired, sometimes even before it occurs.

And yet, today, Mycroft is eerily silent, and the ship right along with him.

They are truly alone.


	4. Chapter 4

**Notes for the Chapter:**

> A portion of the dialogue in this chapter was taken from TRF.

John abandons his medical kit in the access tunnel on Level 3 and climbs blindly, as quickly as he can manage, until his legs are burning and his heart is threatening to break free of his chest. The first time he takes notice of his surroundings, he’s on Level 10--back where he started. The robots are below him, climbing slowly but steadily, their lights cutting beams through the darkness. They whir and click with such frequency that it sounds as though they are chattering with one another, and perhaps they are.

John reaches through the hole between Levels 9 and 10 and pulls the hatch closed, sealing off the ladder and throwing the access tunnel into complete darkness. He stumbles forward down the corridor, ears straining but picking up nothing apart from the blood pounding in his head.

Twenty minutes later, he’s made it all the way to Section 100, and another ladder. He climbs with pinpricks at his back, knowing the robots are following him relentlessly, even if he can’t see them.

There are lights on in the tunnel on Level 35, and John collapses there, chest heaving, clothing soaked through and clinging uncomfortably to his skin. Every door he’s come across has been sealed so far, and he fights down a crushing wave of panic. The tunnels are narrow--not noticeably so, not until one was trapped in them with no way of escape. Then they become cramped, made smaller still by dim-to-nonexistent lighting. John breathes, deeply and slowly, through his nose, and tries to think.

He has only a few bullets left in his gun and an army of robots advancing on him. He can only keep running for so long; they can keep it up indefinitely. The robots are light, but sturdy. A bullet can cut through their outer plating, as John now knows from experience, but landing a physical blow with fists or feet probably wouldn’t do much damage.

All right, he can’t beat them, not with what he has on his person, and he can’t get away from them... so what does that leave?

John groans and tips his head back against the wall.

Down the corridor, beyond where he can see, there is a _whir_ , a _pop_ , and then the sound of dozens of tiny legs clattering across the floor.

John pulls himself up, his muscles protesting every movement.

This isn’t going to be pleasant, but at least he can face it on his feet.

\----------

Sweat beads at the nape of Sherlock’s neck and speeds in rivulets down his spine. He’s sprawled on the floor of the Engine Room, buried up to his waist in a maintenance hatch, pulling apart and connecting delicate wires in an effort to reprogram the ship’s internal sensors. He needs to find out where John and Lestrade are, but searching on foot throughout the entire damaged city is foolhardy at best, and at worst will see them all dead.

Their only hope-- _his_ only hope--is to filter out all the other people that the sensors are picking up, until they are narrowed down to just two.

The only ones that matter.

Sherlock has no doubt that Moriarty is watching him, but the man has made no further attempts at contact and Sherlock isn’t in the mood to chat.

He fits together the final two circuits and then crawls out of the hatch. He pushes himself up onto his knees, his aching joints protesting the movement, and glances at the computer screen suspended above him. On his first attempt, he had managed to eliminate fifty percent of the green dots; now, he has cut that number in half.

It still isn’t enough. The ship is too large, and they have too many inhabitants.

Suppressing a groan, Sherlock squeezes back into the maintenance hatch and tries to figure out where he went wrong.

“Any luck, my dear?”

Sherlock ignores the question, but decides to keep Moriarty talking. Maybe he’ll give something away without even realizing it.

“Some of those breaches weren’t made naturally,” he says as he pulls apart his earlier work. The schematic above him shows the damaged areas of the ship, and some of the breaches are much too large to have been formed by anything flying past them in this part of space. “There’s no way the Yard would have suffered that much damage from a cloud of micrometeoroids. I’d wager you used bombs for most of the hull breaches.”

“Mm, very good. The micrometeoroids wouldn’t have inflicted the amount of damage I wanted, but they’re a nice added _flair_ , don’t you think?”

“Are there more? Bombs, I mean.”

There’s a smirk in Moriarty’s voice.

“I think you’d be disappointed in me if I said _no_. And I know how much you _loathe_ disappointment.”

Above Sherlock’s head, the clock in the corner of the computer screen marks the passage of another minute.

Two hours to go.

\-----------

The robots are closing in.

John, never one to run from a fight, nonetheless finds himself backing up rapidly. He throws up a hand in front of him, palm out, as though that gesture could possibly stop them. They neither speed up nor slow down--they know they will catch him eventually.

If the robots were people, he would try to fake a distraction and then make a break for it. But it’s impossible to distract a robot, not even one designed to analyze and problem-solve in any number of situations -

_ Oh _ .

“Right, you want to fix things, is that it? That’s your... _purpose?_ ” John mutters, more to himself than the robots, though in his imagination they have just given an affirmative _click_. His back collides with the wall, and he stops moving. The robots do not.

“Well then, boys, piece of advice,” he says quietly, pulling the gun from his belt. He holds it out at shoulder-height, aiming it at the wall across from him. “You really should have reinforced this ship better.”

He unloads the rest of the bullets in his gun in rapid succession, grouping them close together so that an entire chunk of the wall weakens, breaks, and gives way under pressure of the relentless vacuum. Air starts to rush from the tunnel, sucked out into space, and the robots--as predicted--start to flock to the growing hole.

They have their priorities, after all. It would seem that Moriarty didn’t think to tamper with that portion of their programming.

John fights the pull of the vacuum with a strong grip on the wall, turns, and bolts down the corridor.

This time, the robots don’t follow.

\----------

Sherlock finally narrows the live schematic down to fifty green dots that are scattered around the screen. Some he can rule out automatically based on location, knowing that John or Lestrade would only be in certain parts of the ship, but it’s still not enough. He brings down his hand in frustration on the computer panel, and the smack of it rings through the empty and still room for several long seconds.

Silence.

He’s not used to it, having lived his entire life with engines beneath his feet and a brother who tracked his every movement. He hasn’t gone more than three days since his eighteenth birthday without Mycroft making contact with him in some manner. Now, they haven’t spoken since Monday, and while he doesn’t necessarily _miss_ Mycroft by any stretch of the imagination, he finds himself... adrift. Cut loose. He has nothing to fall back on, not this time.

Sherlock jabs uselessly at the controls on the computer panel, trying to call his brother. It hasn’t worked the past three times he’s tried it, and the main control room is dark according to the ship’s schematic. He tries anyway.

“Come on, _come on_ ,” Sherlock hisses into the persistent silence. “For once in your life! Do I have to say it?”

He leans over the controls, bracing his hands on the flat computer panel.

“I need you, Mycroft,” he mutters. “Do you hear that? I _need_ you.”

“Too bad he isn’t coming, then, isn’t it?”

Sherlock leaps back at the unexpected voice, and fights down visible anger.

“What do you want now?” he growls at Moriarty.

“I can see why Mycroft so _enjoyed_ being hooked into the computer. It’s exhilarating. Have you ever tried it, my dear?” Without waiting for an answer, he goes on. “Of course, Mycroft was a little slap-dash about the whole thing, wasn’t he? Part flesh, part machine, not human but not computer either. He’d been hooked into the network so long, he didn’t know what to do with himself when I disconnected him.”

“What have you done to him?” Sherlock asks, dread sitting uncomfortably in his stomach. Mycroft hasn’t left the main control room in close to a decade; he’s been part of the ship for even longer.

Moriarty ignores his question.

“He could barely even walk when I had him... removed. Have you ever _heard_ of anything so pathetic?”

“One person might come to mind,” Sherlock retorts.

“Oh, oh, _careful_ with that tongue, my dear. I could do so _very many_ things here, you know, now that I have _wrested_ complete control of the computer from your brother,” Moriarty muses. “I could alter you, Sherlock. Perhaps you aren’t _quite_ the detective people believe you to be.”

Cold floods Sherlock’s veins.

“What?” he blurts despite himself. Moriarty chuckles.

“There are so many things I did _before_ taking over this wondrous piece of technology. _Consulting criminal,_ as you so aptly put it at our first meeting. And business has been booming, Sherlock. Who do you think killed that woman your little _pet_ was slaving over yesterday morning? Her husband wanted her dead... and since he came to me, that’s exactly what happened.” Sherlock can almost hear Moriarty smirk over the line. “But petty crimes become so _tedious_ after a while, don’t you agree? _Please, Jim, will you fix it for me?_ But now, with this computer--with this _ship_ \--I can do anything. I am _limitless_. And the first thing I’m going to do is erase you.”

“You can’t do that,” Sherlock says automatically. “You can’t erase a _person_.”

“Oh, but I can! _Sherlock Holmes is an ordinary man_. That’s the easiest way to sell a lie, Sherlock, didn’t you know? Wrap it up in a truth, makes the whole thing more palatable. More _believable_. Especially when it’s something you want to believe. No one _wants_ to believe you’re as clever as you are; they want you to be ordinary, down at their level. And you know what? I can give that to them, Sherlock. You hired actors to be the murderers, didn’t you? Maybe you even got bored, concocted a few of the puzzles yourself and then solved them with the whole Yard watching you. _I can make you into anything I want_. And there’s nothing you can do about it.”

_ “You’re insane,”  _ Sherlock hisses through his teeth.

“You’re just getting that now?” Moriarty chuckles. “Run along now, Daddy’s got work to do. And you have a choice to make, don’t think I’ve forgotten. You’re stalling, my dear. Out you get!”

A sudden hissing noise fills his ears, coming from high above his head. Sherlock glances up, and sees that gas is starting to pour out of the vents affixed to the ceiling.

He doesn’t wait around to see what it will do to him, and bolts from the room.

\---------

Lestrade is, very nearly, in the middle of the ship. The Yard is on Level 17. Sixteen decks below him, the engines are still; eighteen decks above his head, the main control room sits in eerie silence. All of the lifts are down, and emergency electrical power is questionable at best. He has a torch he took from his desk drawer, in addition to his weapons, and little else. He’s going to have to make a climb for it, if there’s any hope of him reaching the main control room at all.

He finds an access hatch in Section 22 and pries it open with the blade of his small knife when the panel refuses to respond to computer controls. He climbs in, finding the access tunnel thrown into partial darkness as the emergency lights flicker and threaten to go out entirely. Lestrade sighs, and feels his pockets for the torch. He doesn’t pull it out, just reassures himself that it’s there. He can navigate a ladder in the dark, if need be, and there’s no sense in using up the light right now. He might need it in the control room.

He locates the ladder that services this side of the ship and takes a deep breath, steeling himself. Eighteen decks is a hefty climb on a good day, and this is certainly not one of those.

But the ship is dying around him, and he can’t let that happen without a fight.

\----------

Sherlock runs, though he doesn’t know where he’s running to.

Perhaps it would be more accurate to wonder what he’s running _from_ , but Sherlock doesn’t permit himself the luxury of following that train of thought. It is irrelevant, and he needs to focus all his concentration on two things.

_ Find Lestrade. Find John _ .

“Ninety minutes, my dear,” a voice says as he jogs down a corridor several levels above the engine room, and Sherlock forces himself to go faster. The voice follows him anyway, the ship’s construction allowing for communication nearly everywhere.

“Until _what?”_ he snaps, deliberately obtuse.

“Until I take matters into my own hands, and kill them both.” There is a beat of silence. “Surely you saw _that_ one coming, Sherlock.”

His name, _his name_. Why did Moriarty always call him by name, and his given one at that? It grates on his already-brittle nerves, and Sherlock grinds his back teeth in irritation.

“I _am_ this ship, Sherlock. I know every rivet, every bulkhead. I know where your two... _toys_ are. And if you don’t find them within the allotted time, I _will_ kill them both. So I would suggest haste, Sherlock.”

“Why three hours?” Sherlock flies past a computer panel, stumbles to a halt, and then backtracks hastily. He calls up the screen and then tries to tap into the internal sensors. The last computer was obstinate, yes, but perhaps this one would be better... “Back in the engine room, you said _three hours._ But the compromised areas won’t run out of air for much longer than that. So why _three hours_?”

“Why not three hours?” Moriarty chuckles. “Eighty-eight minutes, by the way. Hurry along, now.”

Sherlock closes his eyes, blocking out unnecessary sensory input.

_ Think _ .

John had been in the Infirmary when the accident occurred, but Moriarty had said something about repair crews breaking through to the lower levels. The Infirmary was on Level 10--was it under siege, somehow? Why would repair crews need to go through the Infirmary to get to the lower parts of the ship?

It didn’t make sense, which meant that John had likely left the Infirmary. In a crisis such as this, the only thing that could get him to leave his post and his patients would be serious injuries in other parts of the ship. And in a disaster such as this, John would be forced to use the internal access tunnels, as all the lifts were offline.

And Lestrade... where would Lestrade have gone? The Yard, under normal circumstances, but Sherlock knows that portion of the ship has been evacuated due to heavy damage.

_ No _ . He has to be more basic than that. What is Lestrade’s natural instinct, in a crisis or times of hardship? What is his default?

_ To fix things. _

It had been his automatic reaction years ago, when Sherlock had first stumbled across his path. It’s a default state of being for Lestrade. And he isn’t as much of an idiot as Sherlock likes to point out at his crime scenes. He is competent in a number of different ways, Sherlock knows, and if he can’t fix things from the Yard, he’ll go straight to the heart of the ship and do it from there, if necessary.

“Oh, my, what have we here?” Moriarty croons as Sherlock opens his eyes, fixing his gaze unseeingly on the panel in front of him, which is now unnecessary. “You’ve come to a decision, haven’t you? What fun! This is finally getting interesting. Which one of them is it, my dear?”

_ “Sod off _ ,” Sherlock snaps finally, shoving away from the computer panel and sprinting down the corridor. He has to find an access tunnel.

He needs to get to Level 35, _now_.

\----------

Sherlock scrambles into the first access tunnel he can find and climbs until his legs threaten to give out and send him tumbling back down all the levels he has just passed. Gasping for breath, he pauses on Level 30. It takes several minutes for the sound of his racing heart to fade from his ears; when it does, he realises that he isn’t alone.

A high-pitched _whir_ reaches his ears, and a repair bot hurtles around the corner, flashes by Sherlock, and disappears down the corridor.

Odd, he thinks. There aren’t any microbreaches on this level, according to the schematic. Why is there a robot here, then?

Probably for the same reason why none of the repair bots seemed to have made any effort toward repairing the breaches--Moriarty has tampered with them, Sherlock would guess. He’s intrigued, to be certain, but he can’t spare a thought right now for whatever poor soul Moriarty has decided to target with that particular distraction.

He needs to find Lestrade.

Minutes later, he is forced to pause on Level 35, his body betraying him in increasingly infuriating ways. Now his arms have joined the rebellion his legs are staging, each muscle gone weak and rubbery, and every step up the ladder might be his last. But Sherlock can’t fail now, not when he’s so close to his goal.

Another repair bot whips past him while he rests, and two more scuttle along the floor just beyond reach of his feet. It’s almost as though they are gathering; converging on a single point.

And then, from down the corridor: “ _Oi, you stupid bastards, don’t you have anything better to do?”_

Sherlock’s breath stills in his chest.

_ John _ .

He hesitates, and hates himself for it. Lestrade is likely on this level somewhere... but John is _here_ , _now_ , and in trouble.

And maybe, this way, he can save them both.

Sherlock shoves himself to his feet and, with a grunt, runs toward the sound of John’s indignant voice.

 


	5. Chapter 5

Lestrade arrives on Level 35 out of breath and sticky with perspiration, but he can’t afford to stop and rest. The main control room is only minutes away, and then maybe they can end this whole ordeal.

He dashes down a dim corridor and ducks under a bulkhead that is frozen halfway through the act of closing. The cabins are eerily quiet as he jogs by them. He’s in Section 17, and the main control room is in Section 1.  As he nears the non-operational lift, a noise that he can’t identify catches his ears. It eventually solidifies into men’s voices, and when he rounds a corner he nearly slams headlong into Sherlock.

“Sherlock!” he gasps, fighting the urge to grab the man in a crushing embrace. Sherlock looks just as startled--and just as torn--as he. But then Lestrade realises that they aren’t alone, and he tries to make sense of the scene around him. 

Both Sherlock and John are panting, John leaning against the wall while he tries to catch his breath. Half a dozen of the ship’s small hull repair bots are scattered around them, all in various stages of deactivation. Some are already still; others are giving valiant, final twitches before shutting down for good.

“Good lord,” Lestrade mutters as he takes in John’s clothes and the blood drying on his face. “What happened, mate?”

“Those damned robots,” John spits. “The - the hull repair ones. Moriarty reprogrammed them. They can’t distinguish between metal and flesh, so they’ve been targeting me as something that needs to be _fixed_. Sherlock disabled them.”

“Feedback loop,” Sherlock says distractedly, pulling out his mobile to--presumably--check the time. “Fairly simple, I only needed one to manage it. They’re all connected to one another, like one massive consciousness. Something goes wrong with one’s programming, they all feel it.”

“Moriarty?” Lestrade asks, ignoring the bit about the robots which, frankly, largely goes over his head. He hasn’t heard the madman’s name spoken in over a year, but truth be told, he isn’t surprised to learn that Moriarty is capable of engineering something on this scale. “He’s the one behind all of this?”

“Yes, but I’ll explain on the way,” Sherlock says hastily. “We _must_ get to the control room. We haven’t got time to waste on idle chat.”

“That’s where I’ve been headed. Either of you have a weapon?”

“Got my gun,” John says, still trying to catch his breath. “Doesn’t have any bullets left, but it’s better than nothing.”

“Figured you wouldn’t have one,” Lestrade says when Sherlock remains silent. He digs the penknife out of his pocket. “Take that for me, mate, and give an old man peace of mind, eh? Right. Let’s go.”

\------

They make it as far as Section 5 before they come across a series of cabins that still have occupants in them. Sherlock hesitates briefly, but then makes noises about moving on--five cabins aren’t worth the mystery awaiting him in the main control room. Lestrade goes grey and looks torn. John knows immediately what he’s going to do.

“You two go,” he orders briskly. “I’ll meet up with you in the control room.”

“But -”

“No, Sherlock, don’t even try,” John interrupts sharply. “I’m no use to you in the main control room. I don’t know a thing about computer programs, but you both do. So you two handle Moriarty; I’ll take care of these people.”

Sherlock looks as though he’s about to argue further, but Lestrade grabs his elbow.

“He’s right,” he says, “and we need to keep moving. Be careful, John.”

John tries to crack a grin, but it feels all wrong on his face.

“You know me,” he says lightly, “never one for risks. Now _go.”_

\------

“So, Moriarty,” Lestrade says when the silence after John’s departure becomes too much. He and Sherlock are making their way down a corridor with only two torches to light their way. The lights in this section of the ship have failed entirely, even the emergency ones. “What’s he want this time?”

Sherlock shakes his head a moment, and then says, “He’s bored.”

“He took over the ship because he was _bored?”_

“He strapped bombs to six innocent people last year because he was bored.” The silence that follows is hesitant, and Lestrade knows that Sherlock is going to continue. After a minute, he says, “ _I_ once blew up your kitchen because I was bored.”

“You’re not like him,” Lestrade says at once. “You’re different.”

“Am I?” Sherlock kicks a twisted piece of metal out of his path--debris from the accident. “If it had not been into your hands I fell all those years ago, where do you think I would have ended up?”

Lestrade stops. Sherlock doesn’t notice for three full paces, and then turns around, shining his light full in Lestrade’s face.

“What?” he says impatiently. “We’ve got -”

“You did, though,” Lestrade says softly. “Fall into my hands. So what does it matter what may or may not have happened otherwise?”

Sherlock looks as though he wants to argue further, but then he simply shakes his head again and says, “Come. We should keep moving.”

They pass through three more sections in silence before Sherlock breaks it again, wrenching Lestrade from his troubled thoughts.

“You’re wrong.”

“Hey?”

“You,” Sherlock’s eyes flick to him, “are _wrong_.”

“Yeah, got that, but what about this time?”

The pause that follows is lengthy, and Lestrade doesn’t believe he’ll get a response until Sherlock speaks again.

“About what you said back there. You aren’t _old_.”

Lestrade snorts. 

“I could be your father.”

“Only if you started in your teens.”

“My parents did.” Lestrade softens his words with a crooked smile. “I _am_ old, but it’s all right. It doesn’t bother me like it used to.”

And isn’t that the truth, Lestrade thinks as they set off once again. Five years--hell, even _three_ years ago--that wouldn’t have been a sentence he ever could have uttered. Things were bad when he first met Sherlock, an event that coincided with his fortieth birthday and seemed to drive home the fact that his generation would be gone in another few decades, leaving humanity’s fate in the hands of humans who had never been to Earth. It had been difficult for Lestrade to reconcile sleeping with--and, eventually, coming to care for--one of the _ship rats_ , and he had spiraled during their first two years together. But somehow they had managed to pick one another up; had even kicked their respective addictions together.

No, it doesn’t bother him any longer that he’s growing older, even with a lover eighteen years his junior who could certainly do better than a harried Inspector from Scotland Yard.

It doesn’t bother him, _because_ of Sherlock.

“Sherlock?”

Lestrade slows to a halt. Sherlock, some feet ahead of him, stops and turns around.

“What now, Lestrade?”

A thousand words claw at Lestrade’s tight throat.

_ You’re amazing. You’re bloody brilliant and downright gorgeous. You’re infuriating and spectacular, and sometimes I don’t know what to do with you but I wouldn’t trade that for the universe. _

Instead, he says, “This is my grandfather’s ring.”

He holds up his left hand, and the gold band he’s worn there since his eighteenth birthday glints in the beam of Sherlock’s torch.

“Yes, I’m aware,” Sherlock says slowly, confusion furrowing his brow. “Look, this isn’t really the time -”

“It was his wedding ring,” Lestrade interrupts. “It’s the only thing left of him, actually, the only thing my mother had time to grab before we left the planet. And... And I always thought, if ever I found someone, someone as important and rare as this... I’d give it to them.”

Even in the darkness, Lestrade is sure that Sherlock has lost what little colour he had left in his face.

“Lestrade -” he starts, and then stops abruptly. “You are being foolish.”

“No,” Lestrade says with a laugh. “No, I think this is probably the wisest thing I’ve done in a while.”

Lestrade slides the ring off thickened fingers with minimal difficulty.

“Take it,” he says, holding it out. “Please.”

“I can’t -”

“You say,” Lestrade interrupts, “that you don’t know where you’d be now if you hadn’t fallen into my hands. Well, the truth is... I don’t know where I’d be without you. And I also don’t know if we’ll see tomorrow, but I _do_ know that you’re the reason I get up in the mornings. So... take this. For me.”

Sherlock, his face carefully neutral, considers the ring for a beat before plucking it from Lestrade’s hand and sliding it onto his own.  It fits only because his hands are warm and swollen from their exertions, and Lestrade decides that he likes the look of it on Sherlock’s hand.

They then stare at one another, silent, until Lestrade finally clears his throat.

“Keep moving?”

Sherlock nods briskly, almost relieved. 

“Yes.”

They press on.

\------

The sliding door to the control room is open only a fraction, and there is nothing but darkness beyond. Lestrade curls a hand around the door and shoves it open a few more inches, enough so that he can slide a shoulder through and force it open halfway. He then pulls out his torch and flips it on again.

A man’s body is propped up in a corner, a blanket from an emergency first aid kit drawn up to his shoulders. Dried blood cakes his face, and his eyes have been closed. His death looks like it was painful, and Lestrade sends up a swift thanks that it appears to have also been quick.

Another man is slumped over his workstation, but his back rises and falls, indicating that he’s still breathing. He has simply been knocked unconscious. There’s an unconscious woman next to him. Lestrade verifies that they’re both relatively unharmed otherwise before casting a glance around the rest of the room.

In the center of the room, up on a dais, is Mycroft Holmes’s empty chair--his home for the past ten years. Wires and cables hang from the ceiling and snake up from the arms of the contraption. Once, they had hooked into his mind and body. Now, they hang loose, and some had obviously been ripped away in a hurry--those still have blood on the ends of them. 

Mycroft is nowhere to be seen.

Lestrade lets out a low whistle as he surveys the chaos. Sherlock, if he is affected by any of this, doesn’t show it. He turns to the controls instead.

“Right, then,” he mutters to himself, bringing a computer panel back to life with just a touch, “let’s see what’s been going on here.”

All around the room, one by one, computer screens start to flicker on again. Lestrade taps the screen of the one nearest him while Sherlock busies himself with another. 

According to the computer, at least two hundred cabins have lost atmosphere. If they were occupied, then at a minimum the ship has lost that many people. Casualty reports from the Infirmary indicate that dozens more are injured, many gravely, and that the medical staff has lost a good number of people.

“Sherlock, take a look at this,” Lestrade says finally, his gaze drawn to the clock at the corner of his computer screen, and Sherlock comes to stand over his shoulder.

“Interesting,” Sherlock mutters under his breath, staring at the readout. The clock is counting down, not displaying a time, as Lestrade had first believed. 

“Yeah, strange, isn’t it? Why do you think it’s doing that?”

Sherlock shakes his head. 

“Moriarty has been so adamant about the _time_. He gave me five hours to figure out how to repair the breaches in my cabin. Having passed that test, Moriarty then gave me only three hours to find you and John. But I found you, and yet the clock is apparently still ticking. We’re down to less than one hour. But _what happens_ in one hour?” Sherlock glances at Lestrade. “This section of the ship is safe. Relatively, at least. It could survive for several more months even if we don’t fix all of the breaches. So what’s so important about one hour from now?”

Sherlock’s face lights suddenly, and he whirls away. He jogs over to Mycroft’s chair and sits in it, heedless of the bloody wires dangling in his face, and starts to manipulate the computer interfaces on the arms of the massive chair.

“He’s up to something,” Sherlock mutters. “He _must_ be. And I don’t just mean the breaches and the robots and the _game_.”

“That’s all a distraction,” Lestrade ventures, cold flooding his veins, and Sherlock nods.

“Very likely. But what could he possibly need to distract us from?”

“Something big,” Lestrade puts in. He folds his arms across his chest and watches Sherlock work. “But he’s already done about the biggest thing there is, and that’s to connect to the main computer. He _has_ the ship. What could be bigger than that?”

Sherlock blinks, and looks at him.

“Unless...”

Lestrade feels his eyes widen.

“Unless... unless he’s not quite as connected to the ship as he wants us to believe.”

Sherlock springs from his chair and bolts across the room, heading for the main computer panel. Lestrade can only guess at what he’s looking for, but his expression is frantic.

And then, a moment later, it is triumphant.

“Look at this,” he breathes, and Lestrade comes to stand by his shoulder. He can’t make sense of the lines of code Sherlock is pointing at as he taps the computer screen with one long finger, but Sherlock’s expression tells him that they have stumbled onto the key to this whole ordeal.

“What is it?” Lestrade asks.

“This entire thing,” Sherlock says slowly, “was manufactured by Moriarty as a _distraction_. The meteoroids, the _game_ , getting me to choose... he needed to keep me busy. He knows I’m the only one on this vessel capable of figuring out his plan, and the only one capable of stopping him. And so...”

“And so what?”

Sherlock looks up. The dim red light emanating from the computer screen lights his face from below, and the strange shadows cast across the sharp planes of his face make him appear severe.

“And so he manufactured a distraction built around the only thing in my life ever to give me pause,” Sherlock says gravely.

Lestrade stares at him blankly for a moment, uncomprehending--and then he flushes. He breaks Sherlock’s gaze, passes a hand over his mouth, and finally says, “What’s his big plan, then? Why’d he need you out of the way?”

“He’s trying to integrate himself into the computer,” Sherlock says in a low, rushed voice. “He’s _trying to become the ship_. But it’s not an instantaneous procedure. It took Mycroft _decades_ to become what he is now. Moriarty figured out a faster way, I don’t know how, but he’s manufactured this entire day so he can manage it unmolested. And he’s nearly there. Fifty-five more minutes and we’ll have lost the ship. Forever.”

“How do we stop him?”

But at that moment the door creaks open again, and John staggers through.

“Got everyone out,” he says before they can ask. His eyes flick to the bodies of the staff strewn about the room.

“Unconscious, near as we can tell, except for the one,” Lestrade says quickly as John starts for the nearest staffer. He begins checking them over anyway, and Lestrade turns back to Sherlock and repeats, “So how do we stop him?”

“Oh, my dear Inspector,” a voice croons from the intercom. Red lasers cut through the darkness, and bright dots begin to dance over Lestrade and John. “You _don’t_.”

\-----

“You didn’t really think it was going be as easy as all _that_ , Sherlock dearest?”

Sherlock’s gaze darts between Lestrade and John, and he watches in horror as the two of them are caught in the beams of a dozen snipers, red dots moving about their chests and foreheads, any one of the points a perfect kill shot. John rises from his crouch, slowly, holds his hands up in the air and locks his jaw in anger. Lestrade doesn’t move, except for his eyes, which settle on Sherlock.

“I _did_ say that you were going to have to make a choice,” Moriarty goes on. “And I wasn’t about to leave that up to chance, now, was I? You certainly didn’t think I was going to let it happen without an audience; where would be the fun in _that?_ And don’t bother looking for the snipers, dear, this is all automated and completely under my control. _”_

“Sherlock, what’s he talking about? What choice?” Lestrade asks, a warning in his tone. Six snipers trained on him, and he still finds the reserves to be scolding. 

“Shut up, Greg,” Sherlock snaps.

“Oh _Greg_ , is it?” Moriarty coos. “That’s a new one.”

“Choice, what do you mean _choice?”_ Sherlock asks instead, knowing perfectly well what Moriarty means but trying to buy himself some time to think. 

“It means, dear,” Moriarty says, his voice silk, “that at your word, one of these dear boys will live... and the other will get a bullet placed in his brain.” 

“Why?”

“Because it amuses me.”

“And if I choose neither?”

“Then they both die.” There is a pause. “You have fifty minutes, Sherlock. Take your time. _Make the choice._ ”

“Don’t you dare,” Lestrade says when Sherlock opens his mouth, his words coming immediately on the heels of Moriarty’s. “You know what that means, don’t you? Fifty minutes until integration. You find out how he’s doing that and you _stop_ him, Sherlock. Don’t bother with this game of his.”

“Don’t be a fool, I’m not going to play his _game_ ,” Sherlock sneers. He curls his hand into a fist to quell the tremors suddenly wracking it, trying to get his thoughts under control. “I’ll get you both out of this, just - just give me a moment to think.”

“You can’t do both,” Lestrade says levelly. “You can’t save the ship _and_ the two of us.”

“I _can.”_

Sherlock whirls away and goes over to the nearest computer station, attempting to tap into it and see if he can access the controls for the automated snipers. 

“You can’t,” John breaks in gently. “Greg’s right. The ship is more important. You have to save it, Sherlock.”

“Don’t you dare put us before the lives of everyone else on this vessel,” Lestrade says, firm. “Or I swear to God, Sherlock Holmes, I will _never_ forgive you.”

“I don’t care about the bloody _ship_ ,” Sherlock snarls, irritated. The ship doesn’t matter, and why should it? London City is only interesting because of John; only enjoyable because of Lestrade. Without them, the ship is nothing. 

Without them, _Sherlock_ is nothing. 

“That’s irrational, and you know it,” Lestrade admonishes. “Even if you were to get us out, we’d then be living on a ship under Moriarty’s command. What kind of a life is that?”

“Provided we live long enough after that to _have_ a life,” John mutters under his breath, and Sherlock shoots him a glare. Why can’t they _see_ , why can’t they understand? What good is the ship to him if they are no longer alive? There’s no way he’d ever choose ten million strangers over John and Lestrade.

“The clock is ticking, dear,” Moriarty cuts in. “Heartwarming as this all is, I could use a decision right about now. Which one of them will it be?”

“Fuck off,” Sherlock growls. 

“Well, that’s not very nice. And it’s not really one of the choices I gave you, is it?”

“You can take your choices and shove them up your arse,” Lestrade says suddenly. He lifts his chin in a gesture that Sherlock recognizes means he’s made up his mind--but about what, Sherlock can’t be sure. “He’s not making one.”

“Lestrade, shut up,” Sherlock hisses.

“Quiet, Sherlock,” Lestrade says gently. “You said it yourself, Moriarty spent this entire day trying to distract you. Trying to keep you away from this room. Now, why would he do that?”

“Because the mechanism for his integration is here,” Sherlock answers automatically. Lestrade nods. 

“I’m guessing that the quickest way to stop his integration is by shutting down the main computer, am I right?”

“We can’t,” Sherlock says. The main computer has at least a score of safeguards to prevent it from ever shutting down. Sherlock has no doubt that he could break through the computer’s defenses, but it would take him days. 

They barely have minutes left.

“You can’t,” Moriarty puts in cheerfully. 

“And I’d wager that these things are designed to go off if one of us makes a sudden movement,” Lestrade goes on, heedless of their answers. “Is _that_ right?”

Sherlock and John exchange an uneasy glance.

“Greg,” John says, warning. “What are you going on about?”

“These... automated sniper things. If one of us attempts an escape, they’ll shoot that person, right? Otherwise, what’s the point? No use having them trained on us if John or I could just walk away without any consequences.”

“What of it?” Sherlock growls, panic beginning to tinge his words. 

“Well...” Lestrade trails off, dragging the tip of his tongue across cracked lips as he considers his next words. “Perhaps Moriarty should have thought of that before deciding to use them. Because... turns out, I’m standing in front of the main computer.”

“Don’t - !”

Sherlock’s shout dies on his tongue as Lestrade dodges to the left, his agile movement reminiscent of his football days. There is a brief warning _whine,_ and then six cracks rent the still air.

Lestrade falls.

The shots go clean through Lestrade and slam into the computer console just behind him. Seconds later, the damage causes the main computer to overload, blowing out every station in the room and sending Sherlock and John ducking for cover as fire rains down around their heads. 

And then there is silence.


	6. Chapter 6

Sherlock can’t remember the last time he saw so much red.

It pours from Lestrade’s body, pools around him, drenches Sherlock’s trousers and soaks his hands as he tries to apply pressure to the myriad wounds. And there is red at the corner of his vision, angry flames that crackle and hiss as they eat away at the computers and snake across the floor towards them. 

And then Sherlock blinks, and he’s standing on the wrong side of a glass window, staring blankly into the operating theater while a slew of red-uniformed doctors try to piece Lestrade back together again. Sherlock’s shirt is sticky with blood and more of it has already dried on his arms, and none of it is his own. The copper smell makes his stomach lurch, but he can’t compel himself to move just yet. 

A blanket appears around his shoulders, and Sherlock half-turns to see Molly standing at his side. Her face is lined with strain, but when she looks at him her eyes are too understanding.

“Hello,” she says softly, and all he can do is nod. She adjusts the blanket, wrapping it tighter around him until he finally takes it from her, gripping the ends and folding his arms tightly across his chest. It’s only now, enveloped in the warmth of the fabric, that he realizes that he’s been trembling. “He’s going to be all right. I’ve just spoken with Sarah.”

“Mmm,” is all Sherlock can think to say.

“Would you like me to sit with you?”

Sherlock shakes his head.

“That won’t be necessary,” he says at last. “I’ll not be staying.”

He makes a move towards the door when her voice stops him again.

“I can call, when he’s woken up.”

Sherlock turns and stares at her a moment, unseeing.

“No,” he decides. “I’d rather you didn’t, actually.”

“Don’t you want to see him?”

She actually appears surprised, and Sherlock can barely contain a bitter laugh. 

“No. I don’t.”

 

 

John finds Sherlock in their cabin.

It’s just past four in the morning. From Sherlock’s rumpled clothing and the slump of his shoulders, John can tell that he hasn’t been to bed since the accident, even though he must be weary beyond exhaustion. John, for once, does not chide him for this, nor for the fact that Sherlock is smoking in their rooms.

“Hello,” John says softly. 

He peels off his shirt and reaches for a t-shirt he had thrown over the back of a chair yesterday afternoon. It’s not much of a change, but it’s enough to start to ease his overworked mind and frayed nerves. He has been on-duty for hours; perhaps even for a full day. He’s not entirely sure, in all honesty. He can’t count the number of patients that have crossed his operating table, nor the number of gruesome injuries he's seen. But the number of casualties passing through his doors finally started to slow around midnight, once the technicians broke through the final seals on the ship and freed the rest of his medical staff. John has been granted a six-hour respite because of this. It’s not much, but he will take what he can get.

“John.” Sherlock’s greeting is automatic, and just as quiet.

“How do you feel?”

His cabinmate doesn’t answer him. There’s a butterfly bandage at the corner of Sherlock’s left eye, holding together the skin after a piece of flying metal split it open. A few millimeters to the right and he’d have lost his eye, but it’s still the only injury Sherlock has from the explosion. John escaped with only a few bruises.

Greg was not so lucky.

“Hungry?”

Sherlock shakes his head. John’s not either, and though he doesn’t feel it yet, he knows that it will catch up with him in another couple of hours. The same goes for Sherlock, who hasn’t eaten in longer. John is surprised that he’s still standing, in all honesty.

“If I make something,” he asks gently, “will you eat it?”

Sherlock snorts derisively.

“No,” he says at last.

“Okay... um. Well. We found Mycroft.”

“Yes,” Sherlock says absently. “I know.”

“He’ll be fine in a few days,” John continues, pressing on even though he knows Sherlock would like nothing more than to be left alone. “No lasting damage at all. He’ll be hooked back into the ship in no time.”

“Mmm.”

“They’ve found and disabled the rest of the bombs,” John goes on. “And, well, looks like it’ll take them nearly a month to get the computer restored. The bullets were quite... thorough. But... it can be done. The ship’s been saved, Sherlock.”

John hesitates a moment, and then adds, “He did it.”

“Nearly at the expense of his own life.”

Sherlock’s voice is hollow, and wavers slightly on the last word.

“Greg’s resting comfortably in the Infirmary right now,” John says in a low voice, trying to reassure. “There’ll be some pretty bad scarring, but he’s fine. It was damned lucky those bullets didn’t hit any vital organs, God only knows how they missed. He was even awake and asking about you.”

That earns him a wince, and John instantly regrets his words. To anyone else, Sherlock’s being here now would seem callous when Greg is lying severely wounded in the Infirmary. But John knows--as does Greg--that this is how Sherlock copes with grief.

And guilt.

John shifts his feet, considering the benefit of his next words, and then adds, “It was quick. I doubt he really even felt it at the time. He doesn’t remember it, certainly.”

“Oh, who the bloody hell _cares_ ,” Sherlock snarls abruptly, turning back to the porthole and his cigarette. “Does that change the fact that it happened at all?”

“He’s alive, Sherlock. Focus on that.”

“Why should I?’ Sherlock growls. “What’s the _bloody_ point? It still happened!”

“The point is,” John says gently, calmly, “that it was worth it, to him. It was his decision. You are alive and safe, and... and he’d say that made it more than worth it.”

“Would he now?” Sherlock asks dully. 

“Yes. Of course.”

“Even knowing that I was the one who led him into danger?”

“It was his choice.”

“It was idiotic.”

“Not to him.”

The light glints off Sherlock’s hand as he raises the cigarette to his mouth again. He’s wearing a ring. Another moment of contemplation is spent before John realises that it’s Lestrade’s.

“This is horrendous,” Sherlock announces before John can comment on it. He pulls the cigarette from his mouth and gives it a moment’s thought. “Truly. Whoever thought that low-tar cigarettes were a good idea?”

“Doctors, for one.”

Sherlock grunts. He sticks the cigarette back in the corner of his mouth and shoves his hands into his pockets, and for a while there is silence once again. John’s almost decided to leave when Sherlock starts to speak, his voice hollow and words flat.

“He gave me a choice. Moriarty.” He drops the cigarette to the floor and presses it into extinction with the heel of his shoe. “You, or... or Lestrade. My friend, or my lover.”

“Yes, I’m aware.”

“No, you aren’t,” Sherlock says bitterly. “Before the main control room, before I found you... Moriarty contacted me privately. He told me I could only choose one. I could only choose one of you to save. And I made that choice.”

“Ah,” John says in soft realization, because when Sherlock stumbled upon him in the access tunnel, he had been alone. “Oh, well, I’m sure you made--that is, I’m sure you analyzed the situation logically and -”

“Logic,” Sherlock repeats derisively. “Logic doesn’t even _begin_ to come into it. It was pure chance that I came upon you first. I didn’t mean to. I chose Greg, John.” He searches his pockets for another cigarette and comes up only with his lighter. He spends a long minute fiddling with it before adding, quietly, “I will always choose Greg.”

“That bothers you,” John says in some surprise. Sherlock snorts.

“You spend all your time trying to justify me; trying to make me appear _human_ for your readers. Sometimes, even I can believe it.” Sherlock sighs through his nose. “But you should know... in the main control room, had Greg given me the chance to do so, I would have chosen him.”

“Why are you telling me this?” John asks quietly.

Sherlock gives a huff of disbelieving laughter.

“I don’t know.” His face hardens. “No, I do know. Write about this; don’t write about this. Say I refused to make a choice; say I would have betrayed you in a heartbeat. I don’t particularly care, it’s all much the same to me. But whatever you write, at least you know the truth. I am not the man either of you want me to be. That’s all.”

John swallows, unsure of what to say. 

“There’s nothing wrong with having made a choice,” he says finally. “Especially that one.”

Sherlock doesn’t answer him. For a while there is nothing but the ticking of the clock on the wall; the faint sputter of the engines beneath their feet. Crews have been working around the clock in order to get them back into working order. Absurdly, one of the most disconcerting things about the whole ordeal was how _still_ everything had been. John can’t remember another day in his life when the engines weren’t working. Feeling them beneath his feet again is a relief. 

“We didn’t find his body,” John ventures when the silence becomes too much.

Sherlock shakes his head slowly.

“Moriarty’s? No, you won’t,” he says at last. “There never was a body to find. Moriarty didn’t just hook himself into the computer like Mycroft, John, he _was_ the computer. His consciousness was in there. He discarded the body long ago. I saw the amount of memory he was attempting to access in the main control room. It was _massive_ , almost unbelievably so. He erased hundreds of programs in order to make room for it all, and the integration had lasted hours already when we interrupted it. There’s only one thing that would need that much room in the computer, impossible though it may seem: his mind.”

John is quiet for a moment as he absorbs the enormity of what Sherlock’s trying to say.

“Do you think we’ll hear from him again, then?” he asks finally. “I mean - Greg blew up the main computer. If Moriarty was housing his mind in there, he’d be gone. Right?”

There is a lengthy pause before Sherlock answers.

“Yes,” he says absently. “Yes, I suppose you’re right.”

Somehow, John isn’t reassured by those words, but he can sense that the conversation has drawn to a close. 

“Get some sleep, Sherlock,” John says before he departs. “You look like hell.”

 

 

Sherlock pulls out his mobile when John has gone and brushes his thumb across the display, reading again the words that have seared themselves across his mind since he first received the message hours ago.

_ See you again very soon, darling. _   
_     xx JM _

It’s not over. 

And, truth be told, Sherlock isn’t entirely sure that he is sorry about that. He may be the reason why Lestrade gets out of bed in the mornings, but the promise of future puzzles is what keeps _him_ going through times of hellish tedium. 

But he’s not proud of that, not anymore, not when every time he closes his eyes he sees Lestrade in the crosshairs of six different snipers. He wants to change and knows he can’t and someday, _someday_ , simply wanting won’t be enough anymore. 

Having exhausted his supply of cigarettes, Sherlock makes himself a drink. The liquid burns its way down his throat, the sting unfamiliar and the taste bitter. But he quickly grows warm and numb, his mind going blissfully blank as the alcohol hits his empty stomach, and turns back to the porthole.

Outside, the vacuum slides by as they move through the inky void, and somewhere beyond them, far beyond where he can see, stars are  burning.

“Here’s to you, love,” he says gruffly, bitterly, before downing the rest of his drink. “I hope it was worth it.”

 

 

And later, in the Infirmary, Lestrade takes Sherlock's hand in a too-weak grip, tugs his mouth into a mere approximation of the smile Sherlock is used to seeing, and brushes his thumb over the ring that sits on Sherlock’s left hand.

“Yes. Of _course_ it was worth it.”

 

**Author's Note:**

> Some months back, [geniusbee](http://geniusbee.tumblr.com) shared with me some ideas she had for a _Sherlock_ -in-space AU, and then requested fic set in that ‘verse. I’m not generally one for AUs, but given how often I write amateur-astronomer!Lestrade, I suppose something like this was bound to happen eventually.
> 
> Credit goes to Bee for giving me the general setting. Many thanks to her for allowing me to then take monstrous liberties with the original request and build this universe from there.


End file.
